Multilayered products for use in electronic devices or elements typically include spaced apart conductive circuits that are formed on separate layers of flexible polymer-based film, webbing, or insulating laminate layers. One common method for producing this type of product is to form the customized circuits on individual sheets of plastic film and then join the two sheets of film together after the two circuits have been completely formed. The sheets may be joined together using, for example, a lamination process. This technique can be expensive and entail difficult and time-consuming hand lay-up and registration operations, particularly when the plastic films are very thin, for example, in the range of about 1 mil to 10 mils (25-250 micrometers) thick. The separate films are typically hand registered in stacks and then laminated with rollers or in a press or autoclave under heat and pressure.
Another technique for forming multilayered products includes laminating rolls of web with other layers of web or laminate. The roll of completed product may be cut to any desired length. This technique has certain drawbacks as well. A circuit positioned in the continuous roll of laminated webbing can be difficult to access for the purpose of coupling to a circuit board or to a hard wire connection. Circuit parts can be positioned such that the tail area of a part is exposed along a side of the web for connection as described in U.S. Pat. No. 5,062,016. When this technique is used for a grid type circuit in which conductive traces are aligned in orthogonal X and Y directions, leads to the conductive traces must extend to the sides of the web in order to be exposed for later connection. This restriction on the routing and access points of the conductive traces can result in limitations related to manufacturing efficiency, cost-effective production of parts, and design options for the circuit components and electronic devices that use those components.
Touch screens and electromagnetic digitizers are two types of electronic sensing elements that use a multilayered product. The popularity of technologies that use such sensors has increased significantly over the past several years. Many different technologies have been explored in an effort to produce a high-quality sensor that is reliable and cost effective. Examples of sensor technologies include capacitive, resistive, near field imaging (NFI), acoustical wave, infrared, and force. Common applications for such sensors include computer monitors and mobile and handheld devices, such as personal digital assistants (PDAs) and tablet computers.
Sensors, like many other types of electronic elements or devices that utilize multilayered products, can have many different size and shape limitations. Different sensors may have different requirements for conductive elements and electrically active features in the multilayered product. A single multilayered product and related methods of making such products that can be customized for use in different end products would be an advance in the art.